Different IL‐5 and IFN‐γ Production from Peripheral Blood T‐Cell Subsets in Atopic and Nonatopic Asthmatic Children

Abstract

Defective Th1 and enhanced Th2‐type cytokine responses have been implicated in the development of atopic disease. However, the immunopathology of nonatopic asthma, especially in children, remains unclear, and there have been few studies to compare the cytokine profile in peripheral blood T‐cell subsets between atopic and nonatopic asthmatic children. To document whether atopic asthmatic children have a cytokine imbalance and to compare the cytokine profile between atopic and nonatopic asthmatic children, we investigated the interleukin (IL)‐5‐producing and interferon (IFN)‐γ‐producing T‐cell subsets from peripheral blood mononuclear cells (PBMC). The percentages of IFN‐γ‐producing CD4+ and CD8+ T cells from atopic asthmatic children were decreased, but those in nonatopic asthmatic children were not decreased. In both groups of asthmatic children, the percentages of IFN‐γ‐producing CD4+ T cells were inversely correlated with the peripheral blood eosinophils and had a significant correlation with airway responsiveness (PC20). Thus, we found that the mechanism underlying allergic inflammation of nonatopic asthma is not simple a Th1/Th2 cytokine imbalance. Considering the inverse relationship between IFN‐γ‐producing CD4+ T cells and eosinophilia or airway hyperresponsiveness, IFN‐γ from CD4+ T cells may play an important role in allergic inflammation and airway hyperresponsiveness in asthmatic children.